Blasting-machine



G. HADDOW.

BLASTING MACHINE.

APPLlc/mon man Aua.14, 1919.

Patented Dec. 28, 1920.

2 SHEETS- SHEET lwibvwooeo n G. HADDOW.

BLASTING MACHINE. APPUCATON FILED AUG. 14. 1919. 1,363,585. Patnted Dec. 28, 1920.

2 SHEETS-SHEET 2.

Gf a, eilwdow wit/weones 6G y attomxei UNITED STATES PATENT OFFICE.

GEORGE I-IADDOW, OF TAMAQUA, PENNSYLVANIA, ASSIGNOR TO ATLAS POWDER COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

IBLASTING-MACHINE.

Application led August 14, 1919.

To all 'whom t may concern:

Be it known that I, Gnoncn HADDow, a subject of Great Britain, residing at T am` aqua, in the county of Schuylkill and State of Pennsylvania, have invented certain new and useful Improvements in BlastingMa chinos, of which the following is a specication.

This invention relates to blasting ma-` chines for electrically discharging dynamite or powder charges, the object of the invertA tion being to provide an improved machine of this character constructed in such manner that the current delivered thereby will be up to the maximum capacity of the machine and uniform at all times.

With some. of thel blasting machines at present in use the current is generated by the operation of a rack bar plunger engaged with a gear on the armature shaft. The aforesaid type of machine is unsatisfactory in its operation because the amount of current generated depends upon the force with which the plunger is operated, consequently the current developed is not uniform and often is not up to the current capacity of the machine. This results in frequent failure to fire the charges with a consequent loss of unexploded powder in the bore holes and a loss of labor.

Since the electrical energy generated by the ordinary dynamo electric blasting machine is produced by the push down or the pull up motion of` a push rod engaged directly or through gears with the armature shaft; and since this motion is at the will of the operator, it follows that the strength of the current generated is liable to great variations: to such an extent that when a round of holes close to the capacity of the machine is to be fired, the successful firing of all of them is extremely doubtful. This uncertain behavior of the machine is entirelv due to the varying strength of the mechanical force actuating the apparatus. To avoid these object-ions the present invention contemplates the provision of a machine in which the movement of a rack bar by the operator stores up power in a spring, which spring is automatically released near the end of the stroke of the rack bar and the stored power utilized to impart such a rapid Specification of Letters Patent.

Patented Dec. 28, 1920.

Serial No. 317,472.

and uniform movement to the armature of the machine as to produce current of a uniform strength and up to the capacity of the machine, throughout the return movement of the spring.

A further object of the invention is to provide a machine of the character indicated embodying means for preventing the operator from giving only a partial movement to the rack bar, but compelling said rack bar to be moved its full stroke after it starts in one direction or the other.

Further objects and advantages of the invention will be set forth in the detailed description which now follows.

In the accompanying drawing- Figure l is a ldiagrammatic view of a blasting machine with the parts constituting particularly the present invention, illus` trated partly in section and partly in front elevation and some of said parts being broken away;

Fig. 2 is a View partly in front elevation and partly in section of the actuating rack and the pawl and ratchet disk with the parts in the position they occupy prior to the initial movement of the handle;

Fig. 3 is a view similar to Fig. 2 illustrating the parts in the position they occupy after the downward movement of the rack bar has been completed; and

Fig. 4 is a side view of the pawl and ratchet disk and associated parts.

Like numerals designate corresponding parts throughout the several figures of the drawing.

Referring to the drawing 5 designates a handle that is carried bv an operating rack bar 6. The teeth of this rack bar mesh with a pinion 7. that is connected bv a hub 8, with a pawl farrving disk 9. the pinion. 7 and theI disk 9 being free toturn upon a fixed shaft l0. A. pawl 1l is pivotally connected at 12 to the disk 9, and its hook end -3 isadapted to engage a notch 14, formed in a ratchet disk l5, The ratchet disk l5 is connected by a hub 16 with a gear wheel 17, so that these two parts turn together. The lgear wheel l? meshes with a pinion 18 mounted upon the shaft 19 of a generator 20. This generator is of the ordinary and well known construction used in machines ot this character and its specific construction forms no part ot the present invention, the present invention relating particularly to the actuating means tor the armature shaft.

lt lisapparent that downward. pressure upon the handle 5 will press the rack bar 6 downwardly and will imparta turning movement to the pinion Z and to the pawl carrying disk 9. rlhe paw] 11 engaging' with the notch 14 under the influence ot a spring,` 21 will pull the ratchet disk 15 around in the direction et the arrow c in Fig. 2 and this movement will continue until a pin 22 upon the pawl 11 rides over the curved face 23 ot a fixed cam whereby the pawl will be lifted ont ot engagement with the notch 14 and the disk 15 will be treed from the pawl.

During,` the downward movement of the rack bar 6 a spring' 25 is placed under tension, one end ot this spring` being connected at 26 to the ratchet disk 15 and the other end of said spring being' connected at 2T to the fixed shaft. Consequently when the ratchet disk 15 is treed ot the restraint ot the pawl at the end ot the stroke oi the rack bar, the spring 25 immediately acts to impart a quick return movement to the disk 15 and to the gear 17 that is connected thereto and moves therewith. This results in imparting a quick turning movement to the armature shaft 19 through the medium oi" the pinion 18 as will be readily understood.

An abutment 26 uion the Wear wheel 1'? i :s

contacts with a spring pressed plunger at the end ot its return movement to thereby cushion the action et the parts. )i circuit controlling` lever 2S, is pivoted at and its tree end carries a contact block 30 that is adapted to engage a switch P1 and hold the same 4open. As the driving disk is nearing thecnd ot its revolution and at the moment when the armature is rotating at highest speed, a stop 32 carried by the gear 1T, acts to torce lever 28 against the spring 31, thus opening the i'leld circuit ot the dynamo and throwing the accumulated energy into 'the Vexternal circuit. It is to he understood. that the quick return throw t the gear 1T "is the eit'ective working movement, since a.

one-way clutch 19a serves to prevent the 'movement ot the gear 17 under the direct 'action'ot the handle trom actuating' the generator 20.

To render it impossible to partly push the rack bar 6 down and then pull the saine backwithout "completing the stroke, l provide a clog A. tail 35 extends Jrom this 'dog' .and 'lies .in the path of movement ci carrying positions. :is the rack bar starts downwardly its teeth snap past the lower element Ell et the dog which acts as a ratchet and this movement continues until the rack bar has substantially completed its downward stroke, at which time pin 3G strikes the tail 35 and moves it to the position illustrated in 3; thereupon the upper member 34th ot the dog' snaps into engagement with the teeth ot the rack bar under the intluencc oit the spring' 38 and remains in this position until the pin 37 upon its rip-stroke restores the parts to the position illustrated in Fig. 1.

While the elements shown and described are well adapted to serve the purposes for which they are intended it is to be understood that the invention is not limited to the precise construction set torth but that it includes within its purview whatever changes fairly come within either the terms or the spirit ot the appended claims.

Having described my invention what l. claim is:

1. ln a blasting' machine the combination with an electrical generator, of an actuatingmember therefor, a spring;` connected to said actuating member, a` handle, means for putting the spring' under tension by movement ot the handle in one direction, means tor automatically releasing,- said spring to permit it .to act at the terminatien ot the movement ot the handle in one direction and means in engagement withv said handle throughout its entire travel, actat all points in the travel to prevent reverse movement ot the handle until it has completed its movement.

2. A blasting` machine con'iprising an electrical `generator, an actuating` rack-bar, springv actuated means Yfor imparting working` movement to the generator, connections between said spring actuated means and the rack-bar .tor winding the spring;- by movement ot the rack-bar, a dog, which in one position permits movement ot the rack-bar in one direction only and when in the other position, permits movement in the other direc-tion only and means tor automatically moving` the dog at the extremity ot such movement.

3. ln a blasting` machine the combination with a generator' comprising an armature, a pinion thereon, gear wheel meshing` with said pinion, a lined shaft, a ratchet disk, a sleeve connecting the ratclretdisk and the gear wheel, said sleeve being' tree to turn en the ratchet disk, a pinion 'lined to 'the' pawl disk, a rackaar meshing,` witlrsaid pinion, means 'tor releasing thepawl from of the same in one direction only until said rack-bar has completed its throw.

In testimony whereof I affix my signature in the presence of two witnesses.

GEORGE HADDOVV. Witnesses:

S. R. BEARD, G. A. BILLMAN. 

